We propose to continue and extend studies of the isolation, structure determination, and chemistry of new antitumor compounds from plants. Several novel compounds have been obtained under previous grants. Investigation of these will be completed and work initiated on new problems. The procedures involve isolation, via activity-directed fractionation, of the antitumor active compounds, as well as systematic phytochemical investigation of significant related, but not necessarily active, congeneric constituents. BIBLIOGRAPHIC REFERENCES: Light Petroleum Extractives of Lychnophora affinis, Philip W. Le Quesne, Mary P. Pastore and Robert F. Raffauf, Phytochemistry 14, 1467 (1975). Eremantholide A, a Novel Tumor-Inhibiting Compound from Eremanthus elaeagnus, Robert F. Raffauf, P-K. C. Huang, Philip W. Le Quesne, Steven B. Levery and Thomas F. Brennan, J. Amer. Chem. Soc. 97, 6884, (1975).